Table 4 Ensuring Rigor in Case Study and Qualitative Data Collection and Analysis [45, 46]

• Prolonged engagement with the subject of inquiry. Health policy and systems research tends to draw on lengthy and perhaps repeated interviews with respondents and/or days and weeks of engagement at a case study site.

• Use of theory. Theory is essential to guide sample selection, data collection, analysis, and interpretive analysis.

• Case selection. Purposive selection allows earlier theory and initial assumptions to be tested and permits an examination of “average” or unusual experience.

• Sampling. It is essential to consider possible factors that might influence the behavior of the people in the sample and ensure that the initial sample draws extensively across people, places, and time. Researchers need to gather views from a wide range of perspectives and respondents and not allow one viewpoint to dominate.

• Multiple methods. For each case study site, best practice calls for carrying out two sets of formal interviews with all sampled staff, patients, facility supervisors, and area managers and conducting observations and informal discussions.

• Triangulation. Patterns of convergence and divergence may emerge by comparing results with theory in terms of sources of evidence (e.g., across interviewees and between interview and other data), various researchers’ strategies, and methodological approaches.

• Negative case analysis. It is advisable to search for evidence that contradicts explanations and theory and then refine the analysis accordingly.

• Peer debriefing and support. Other researchers should be involved in a review of findings and reports.

• Respondent validation. Respondents should review all findings and reports.

• Clear report of methods of data collection and analysis (audit trail). A full record of activities provides others with a complete account of how methods evolved.